The psychologist’s view that Paul's problems stem from internal processes like unrealistic expectations and negative thinking is typical of the cognitive model of behavior. This model focuses on how internal thoughts, beliefs, and cognitive processes influence behavior and emotional functioning. It suggests that dysfunctional thinking patterns, such as negative or unrealistic expectations, can lead to problems like poor performance or emotional distress

. In this case, the psychologist is emphasizing internal mental processes rather than external environmental factors (which would align more with behaviorism) or unconscious drives (which would align with the psychodynamic model)

. Thus, the cognitive perspective best explains the psychologist’s explanation of Paul's difficulties.